|Travel Advice||Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.||Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.||Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding, and conservative decision-making essential.||Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.||Extraordinarily dangerous avalanche conditions. Avoid all avalanche terrain.|
|Likelihood of Avalanches||Natural and human-triggered avalanches unlikely.||Natural avalanches unlikely; human-triggered avalanches possible.||Natural avalanches possible; human-triggered avalanches likely.||Natural avalanches likely; human-triggered avalanches very likely.||Natural and human-triggered avalanches certain.|
|Avalanche Size and Distribution||Small avalanches in isolated areas or extreme terrain.||Small avalanches in specific areas; or large avalanches in isolated areas.||Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.||Large avalanches in many areas; or very large avalanches in specific areas.||Very large avalanches in many areas.|
Seward Highway/Portage Valley: Multiple natural avalanches were observed in the paths along the road near Girdwood and in the Portage Valley. Avalanches were running about 75% of the way to the valley bottom.
Seattle Ridge: Riders reported triggering multiple small storm slabs near the motorized uptrack. Nobody was caught in any of the slides.
|Signal Word||Size (D scale)||Simple Descriptor|
|Small||1||Unlikely to bury a person|
|Large||2||Can bury a person|
|Very Large||3||Can destroy a house|
|Historic||4 & 5||Can destroy part or all of a village|
The heavy snow and strong winds from yesterday have buried a variety of weak surfaces, which will keep avalanche danger elevated today. As of 6:00 this morning, storm totals are as follows:
Storm totals were higher in the Portage and Placer valleys. which likely recieved 18+” in the upper elevations. This snow came along with strong easterly winds through most of the day yesterday. The Sunburst weather station recorded sustained speeds of 20-50 mph with gusts of 35-70 mph through 6:00 p.m. Winds in the Girdwood area were slightly calmer at 15-20 mph before dropping down to around 10 mph at 11:00 a.m. yesterday. While we are expecting to see precipitation trickle off today, the problem we are left dealing with is that all of yesterday’s storm snow has buried a variety of weak surfaces that will remain reactive today. This includes a layer of near-surface facets that formed during the cold and clear weather in the first week of the year, pockets of buried surface hoar that formed just before this storm moved in, and the New Year’s rain crust that is buried anywhere from 1-3′ deep in the mid and upper elevations.
Since the new snow is burying these persistent weak layers, we can expect to see sensitive avalanche conditions lingering a little bit longer than normal following this storm. The most likely place to trigger an avalanche will be on steep slopes that have been recently wind loaded. The most suspect locations will be above treeline, near ridgelines, below steep convexities, and in gullies. It may also be possible to trigger an avalanche up to a foot deep on steep slopes sheltered from the winds in the middle elevations. Traveling in the mountains today will require an extra alertness. Seek out feedback as you move around. Look for clear signs of poor stability like shooting cracks, collapsing, and fresh avalanche activity like John mentions in his video from the field below. The current snowpack will need more time to adjust, and today is not a good day to jump out into big terrain.
Loose Wet avalanches: Continued light rain up to 1200-1500′ as of 6:00 this morning will make it likely we will see some loose wet activity in the lower elevations. These avalanches will most likely be relatively small and slow moving, but they can have consequences if they push you into terrain traps like alders, trees, creeks, or rocks. As always, be sure to pay attention to the terrain above you so you don’t get caught off guard.
Shooting cracks at treeline in the Tincan trees yesterday. Since this storm fell on weak surfaces we can expect to see similar signs of poor stability lingering on some slopes today. Photo: Mike Loso. 1.10.2022.
Yesterday: A warm and wet storm brought 10-12″ snow (1.1″ SWE) to Turnagain Pass, 15-18″ snow (1.49-2.09″ SWE) to Girdwood, and almost missed Summit Lake entirely, dropping only 1-2″ snow (0.2″ SWE). Strong easterly winds were blowing 20-50 mph, gusting 35-70 mph at Turnagain Pass until calming down around 6:00 p.m. Girdwood stayed slightly calmer at 15-20 mph with gusts of 30-60 mph before dropping to 5-15 mph with gusts around 15-30 mph since 11:00 a.m. yesterday. Temperatures have been in the upper 20’s to low 30’s F since yesterday morning. Mixed snow and rain has made it up to 1500′ in Girdwood and around 1300′ in Turnagain Pass.
Today: Light snow with rain to 1200′ is expected to subside this morning, with breaks in the clouds possible later this afternoon. We may see another 1-2″ snow before this round ends, with temperatures dropping in the mid 20’s F by the end of the day into tonight. The rain level is expected to drop back down to 500-600′, and light southeasterly winds are expected at 5-10 mph with gusts of 10-15 mph.
Tomorrow: Snow showers are expected to resume tonight, with another 2-5″ expected by the end of the day tomorrow. Right now it is looking like Turnagain Pass will be on the low end of that estimate and Girdwood will be on the upper end. Easterly winds are expected to pick up overnight into tomorrow at 15-30 mph under cloudy skies. Overnight low temperatures are looking to be in the low to mid 20’s, with daytime highs in the mid 20’s to low 30’s. Rain level is expected to stay around 300-800′.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||33||3||0.4||72|
|Summit Lake (1400′)||30||1||0.1||24|
|Alyeska Mid (1700′)||33||4||0.72||47|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||28||SE||9||25|
|12/02/23||Turnagain||Observation: Seattle Ridge||Schauer / Keeler Forecaster|
|12/02/23||Turnagain||Observation: Tincan South Side||Anonymous|
|12/02/23||Turnagain||Observation: Eddies up track||Luc Mehl|
|12/01/23||Avalanche: Sunburst||John Sykes Forecaster|
|12/01/23||Turnagain||Observation: Eddie’s trees||Anonymous|
|12/01/23||Turnagain||Observation: Turnagain – God’s Country||Graham Predeger Forecaster|
|11/30/23||Turnagain||Avalanche: Tincan Trees||Kakiko Ramos-Leon|
|11/27/23||Turnagain||Avalanche: Tincan Ridge||Schauer/ Stiassny Forecaster|
|11/26/23||Turnagain||Observation: Road report: Slide with dirt on Repeat offender||Anonymous|
|11/26/23||Turnagain||Observation: Pete’s North||Ben Sullender|